Typographical casting machine



M E. W. PIERSON 4TYPOGRAPHICAL CASTING MACHINE Filed Feb. 20, 1923 Feb. l0, 1925.

4 /VENTO lll Patented Feb. 1o, 1925,

'UNITED STATES PATENT oFFlcE.

y. EDWIN W. ErEEsoN, vor NEWARK, NEW JERSEY, AssIGNoE To MEEGENTHALEE LINorYrE-coMrANY, A conroEAfrIoN or NEW YORK.

t TYPOGBAPHICAL' CASTING MACHINE.

Application filed February 20, 1923. Serial No. 620,168. j

To all/whom t may concern.'

Be it known that l, EDWIN W. PmnsoN, a citizen of the AUnited States, 'residing at Newark, in the county of Essex and State of New Jersey, have invented certain new and yuseful Improvements in Typographical Casting Machines, of which the following is a specification, reference being had therein to the accompanying drawing.

'lhis `invention relates to typographical casting machines, such as linotype machines of the general organization represented in lll. S. Letters Patent to 0. Mergenthaler, No. 436,532, wherein a type bar or slug is cast in a slotted mold up against a composed line of matrices and thereafter removed from the mold by an ejectonblade which advances from the rear and drives the slug before it into a receiving galley at they front. ln these machines,y the molten metal is intro'- duced into the mold by means of a pump piston or plunger arranged within a melting pot and controlled in its action by a rotary ttl cam which, as is well known, makes one complete rotation for each-cycle of operation of the machine.l The cam is so shaped as normally to maintain the pump plunger in a raised position out of action, but at vone point in its circumference, it is formed with a depression which, at the proper time, permits the plunger to descend under the'action of a strong spring to carry out. the slug casting operation. Under this old arrangement, lit frequently happens that the cast slugs are imperfect, the imperfections being present not only inthe type characters but also in the body portionsr of the slugs. A rather common defect is that the bottom edges of the slu s are hollow or spongy, this beingparticular y true of slugs ofthe largerv sizes. As a result, the ejector blade, in removing such a defective slu from the mold, often embeds itself in the ase of the slug and wedges thev latter tightly in themold, giving rise to considerable annoyance and delays and sometimes causing serious damage to the parts.L The objections referred to are due primarily to the fact that the pump plunger'fails to exert sufficient pressure upon the molten metal throughout the j casting operation,A it being notedV that the Ysprin which'edects the working stroke of t e unger, is anchored to a fixed part of the` machine and hence grows, weaker and weaker as the casting operation progresses.

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In other words, near the completion of the casting operation, the load applied to the plunger (which should be at its maximum) 1s actually at its minimum, due to the lost tension or relaxation of the spring at the time. Theppresent invention is intended to obviate the foregoing objections, and toy this end, it consists specifically in the provision of an automatic tensioning device which will not only keep up the initial tension of Athe spring during the working stroke of the pump plunger but which will actually increase said tension at or near the completion of such Working stroke. ln this way, the molten metal is maintained under an undiminishing pressure throughout the casting operation and thus caused to fill the mold completely. Actual practice has shown that a slug cast according to this invention yis substantially' free from the defects before ,noted, being practically solid throughout and presenting in 'particular a base or bottom edge well adapted to withstand the impact of the ejector'blade in removing the slug frompthe mold. ln the preferred embodiment herein illustrated, the invention is disclosed in the nature of an attachment capable of ready application to the regular linotype machine now on the market, a feature which is advantageous for obvious reasons. rlhe exact construction and o eration of the parts will best be undestood from the detailed description to follow.

Referring to the drawings: Fig. l is a'vertical section taken through the casting mechanism of a linotype machine equipped with the present improvements; and E Fig. 2 is a top plan view, partly in section, of the pump plunger actuating devices.

ln Fig. l,the parts are shown in the relative positions they occupy just prior to the commencement of the casting operation. ln this condition of the parts, the. slotted mold A, carried by a rotary disk A', is closed at the front by the composed line of matrices X presented momentarily thereto' by a carrier or first elevator B, and it is closed at the rear by the mouthpiece C of a melting pot having a throat or passage C2 leading .from a pump well or cylinder C located within the pot. The well or cylinder C contains a reciprocatory pump piston or plunger E adapted to be actuated at casting operation to'inject the molten ice llt).

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metal into the mold A up against the composed matrix line X for the production of the type bar or slug. The pump plunger E is connected by means et a rod or luik la ed laterally bene-ath a further lever E1" which is also mounted loosely on the fixed' rod E4 and has its free end connected to a long helical spring E10 pulling downwardly thereon under a heavy ltension. As well understood in the art, the peripheral edge of the cam wheel E8 is concentric throughout exceptVIV at one portion of its c'rcumterence,

where it is cut away'or fori-ned with a de` pression to provide sloping surfaces E11 and E12. When the machine is at rest, the roller E7 is in Contact with the concentric portion of the cam wheel E8, so that the plunger E is maintained in its raised or inoperative position against the ,opposition of the spring E10, as indicate ir` Fig. l. rlhis condition obtains until the casting period arrives, when the cam wheel (rotating in the direction of the arrow) brings its sloping surface E11 into engagement with theV roller E", which thereupon descends along such surface to the bottom ot the depression and permits-the spring E10, through the connections described, to depress the plunger E and force a charge ot' molten metalinto the mold. As the cam wheel continues to rotate, the yroller E7 is engaged sooner or later by the sloping @surface E12 arid the parts thereby restored to and maintained in their origina-l condition to await the next casting operation.

As thus far described, the parts and their mode of operation are or may be the same as embodied in the commercial linotypc machine. ln prior constructions, however, the spring E10 has been anchored at its lower end to a fixed part of the machine, and.

hence loses much of its tension as the pump plunger' descends, becoming weakest when the plunger is at the end of its working stroke. As a result, thel pressure exerted upon the molten metal during the casting operation correspondingly varies, being at its maximum at the beg'nning of the operation and at its minimum at theclose of the operation. According to the present invention, the initial tension of the spring (i. e., the tension the spring is under at the beg'nning of the vpump stroke) is kept up throughout the casting operation,h so that the pressure upon the mplten'metal will not Maasai lag or drop ol` at stage thereof. lt would probably answer the purpose if the tension of the spring were kept uniform throughout the casting operation so as to cause the pump plunger to exert a consta-nt pressure upon the molten metal, but, in view of the diificulties involved, it is proposed to increase tire tension of the spring at or near the end of the operation so as to build up the pressure at that time.

In carrying out the invention, there is provided a second lever F pivoted at one end, as at F, to a bracket G secured to thel machine frame, and having at its free end a suitable -anchor F4 for the spring E10. Near its free end, the lever F is provided with a set screw or stop F2 adapted to engage a fixed part of the machine Jframe O and limit the upward movement of the lever'. Near its pivoted end, the leve-r is provided with a roller F3 which is adapted to cooperate with a riseror projection/H of a second cam wheel H secured to the main shaft D of the machine. the riser H is shown as being integral with the cam Wheel H (as it might be), but in actual practice it is in the form of a separate piece applied thereto.

ln the condition of the parts just prior to the casting operation, as shown in Fig. l, the lever F is in engagement with the fixed machine frame and holds the spring E10' under the desired initial tension, but when the pumpI plunger E begins 'its Working stroke, as permitted bythe travel of the roller 7 down the inclined surface E11, the roller F3 is at or about such time engaged by the. cam riser or projection H', which then depressesI the lever .F so as to lower the spring anchor F4 at al rate of speed sufficient substantially to keep up the initial tension of the spring throughout the pump strokeA In the present instance, the parts are so proportioned that the spring anchor will be moved at a rate of Speed and for a distance such as to increase the initial tension of the spring as the pump plunger nears the end of its working stroke. The dotted lines in Fig. 1 show the parts in their fully operated condition. When the pump plunger E is restored to its original position in the manner before described, the lever F is lifted back intol engagement with lthe machine frame through the medium of the spring E10, which at the same time is placed under its original or initial tension ready for the next pump stroke. In this connection, i'; may be remarked that the, Iuse ot' the stop y-F 1 is herein resorted to merely because of the fact that the cam Wheel H, which forms 4a part of the standard linotype equipment,

is notV such as toy permit the roller F3 to track thereon. It 'is obvious that it would `be entlrely feasible to employ a continuous cam upon which ,the lroller F3 might track,

In the drawings,

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in ,which event there would of course be no necessity for thestop F2.

The invent-.ion has been shown herein only in preferred form and bywvay of example A to any particular form or embodiment except in so far as such limitations are speciied in thc claims.

Having thus described 1n 1 invention, its construction and mode of operation, what I claim is as follows:

l. In a typographical casting'jmachine, the combination of a mold, intermittently operated and automatically Vcontrolled means for injecting molten metal into the mold at each casting operation, and means for keeping up a substantially undiminishing pressure on the molten metal throughout each metal injecting action. O

. 2. n a typographical casting machine, the combination of a melting spot, a reciprocatory'pump plunger mounted therein, and intermittently operated and automatically cont-rolled mechanism for reciprocating the pump plunger, said mechanism acting to keep up a substantially -undiminishing pressure on the molten metal throughout the working stroke of the pump plunger.

3. In a typographical cast-ing machine, the combination of a melting pot, a rec1procav tory pump plunger mountedl therein, and

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mechanism for reciprocating the pump plunger, said mechanism acting substantlally` to keep up the initial pressure of the plunger on the molten metal vduring its working stroke and to increase said pressure near the end of saidv stroke.

4. Inga typographical casting machine, the combination of a melting pot, a reciprocatory pump plunger. mounted therein, and mechanism forl reciprocating the pump plunger, said mechanism including al spring under tension to effect the working stroke of the plunger, and automatic means for keepup substantially the-initial Vtension of the spring throughout such plunger stroke.

5.l In a typographical casting machine, the

combination ot' a melting pot', a reciproca- `tory pump plunger mounted therein, and

mechanism for reciprocating the pum-p pluner, said mechanism including a sprino uu ei tension to effect the wor ing stroke of the plunger, and automatic means for keeping up substantially t e initial tension of the spring during such p unger stroke and for increasing said vtension rear the end of said stroke.

6. In a t pographieal casting machine, theV combina ion of a melting pot, a periodically operated kpump plunger mounted therein, an vautomatically controlled spring to eii'ect the Working stroke of the plunger, and an automatic tensioning device. acting on the spring during its operation of the plunger to keep up substantially the initial pressure of said'plunger on the molten metal near the end of itsl Working stroke.

7. In a typographicalA casting machine,. the combination of a melting pot, a periodically operated pump plunger mounted there in, an automatically controlled spring to effect the working stroke 'of then plunger, and an automatically shiftable member to which the spring is anchored, said member acting to keep `up substantially the initial tension `of the spring during the working stroke of the plunger;

8. In a typographical casting machine, the combination of a melting pot, a vertically movable pump plunger mounted therein, a spring connected to said plunger and acting constantly to depress it, means cooperating With ,the plunger` to control the action of the spring and to raise the plunger after its depression thereby, and anautomatic spring tensioning device operated during the depression of the plunger to keep up substantially the initial pressure of said plunger on the molten metal near the end of its Working stroke.

9. In a typographical casting machine, the combination of a melting pot, a vertically movable pump plunger mounted therein, an actuating lever for the/ pump plunger, a spring connected to saidA actuatin lever and'acting constantly to depress the p unger,

a cam cooperating With the actuating lever to control the action of the spring and to raise the plunger after its depression thereby, a second lever to which the spring is anchored and which serves to keep up substantially the initial tension of said spring duringV the working stroke of the plunger, and a cam for operating the second lever in `proper synchronism with the other parts.

10. In a typographical casting machine, the combination of a melting pot, a vertically movablepump plunger mounted there in, an actuating lever for the pump plunger,

a s ring connected to-saidlactuatin lever an acting constantly to depress the p unger, a cam cooperating with said actuating lever to control the Vactie-11 of the spring Iand to raise the plunger after its depression thereby, a second vertically movable lever to ywhich the spring is anchored and normally held against upward movement by engagement wlth a fixed part of the machine frame, and a cam acting to depress said secI ond lever duringI the depression of the 125 pump lunger by the spring to up sub stantia ly the initial tension o throu hout such period.

11. n a typographical casting machine,

e latter `the combination of a. melting pot, a. verti 130,

cally movable pump plunger mounted therein, an automatically controlled spring to depress the pump plunger at each casting operation, a vertically movable member to Which the spring is anchored and held nor mally against upward movement, and'auto- `matic means for depressing said member during the depression of the pump plunger by the spring to keep up substantially the initial tension ofi` the latter throughout such period.

12. ln a typographical casting machine,

signature hereto.

EDWIN lV. PIERSON. 

